甘肃洛坝铅锌矿选矿流程考察与优化

Investigation and Optimization of Processing Flowsheet for a Luoba Lead-zinc Mine in Gansu Province

我国铅锌矿产资源丰富,但其自然禀赋差且矿物组成复杂,导致其综合回收利用难度大。甘肃洛坝铅锌矿是一座含铅锌且伴生有少量银、硫的泥岩—细碎屑岩型铅锌矿床,因其矿石性质复杂,较早期形成的矿石性质发生明显变化,导致铅锌分选指标及精矿质量下降。为解决现有选矿生产过程中存在的问题,寻找适宜的改进措施和方法,以提高铅锌资源综合利用效率,在研究矿石性质的基础上开展了详细的工艺流程考察。研究结果表明:矿石中碳质、硅质等脉石矿物含量升高,碎磨过程易于泥化,且吸附性能和可浮性好,这些是影响铅锌分选指标的主要因素;通过优化碎磨工艺参数,减少了碳质、硅质等脉石矿物的泥化程度;在浮选工艺中添加适宜抑制剂,并采用高选择性的铅、锌矿物捕收剂,可显著提高铅、锌精矿品位和质量,大幅提高铅、锌回收率,从而实现该复杂含碳低品位铅锌资源的高效综合回收,并为同类矿产资源的选矿回收提供参考依据。

The lead and zinc mineral resources are very abundance in China,but the lead-zinc metal quantity is much short for further mining.The resources are not of natural endowment,with difficulty of utilization.Type of lead-zinc deposit is variety and associated elements are rich.Sulfide minerals have similar interface properties and are difficult to separate.Widespread as the occurrence of resource is,the ores are mostly very low-grade, complexity of multi-components and difficult of separation. All of this up make it difficult to recover such resources efficiently and comprehensively. It is necessary to carry out systematic process optimization and technical research in order to improve the comprehensive utilization.The Luoba lead-zinc deposit in Gansu Province is a mudstone-fine clastic lead-zinc deposit,associated with a small amount of silver and sulfur.With the long-term exploitation and utilization,the valuable metal content of lead and zinc in the ore decreases,while the content of carbonaceous and siliceous minerals increases,which brings great interference to the separation and recovery of lead and zinc.There are some problems in lead and zinc concentrate production,such as lead concentrate grade decrease,zinc concentrate containing excessive silicon. As a result,the present mineral processing technology and reagent system can’t adapt to the change of ore properties well. Therefore,a systematic process optimization and technical research should be carried out to find out the quality decline of concentrate and the possible problems in the process of concentration,and to explore the difficulties and physical factors in the recovery of lead and zinc flotation,so as to improve the comprehensive utilization level of resources.On the basis of detailed understanding of mineral processing technology and production status,an overall processing flowsheet investigation was conducted.It has been studied that the technical parameters and production conditions of each operation of grinding and floating process.Then the distribution of useful and harmful elements was identified.The problems existing in the production process were analyzed,the physical factors concerning the grade and quality of lead and zinc concentrate were proved.Then put forward a specific improvement program in order to optimize the existing process and technical conditions,and to provide a high efficiency foundation for carbolic lead-zinc resources recovery.The results show that the carbonaceous minerals, such as aphanitic graphite,are of high content in the ore.It is easy to be mud in the grinding process,and has good floatability and adsorption performance.Because of the interaction between the carbonaceous minerals and lead-zinc minerals,the adsorbing quantity of collectors for the lead-zinc minerals in slurry system was less than that of collectors without carbonaceous minerals.The carbonaceous minerals,such as aphanitic graphite,finally entered the concentrates,affecting the recovery and quality of lead and zinc minerals.High-alkali speed flotation technology,has solved the concentration recovery of lead and zinc mineral.But the content of silicon and carbon in lead and zinc concentrates is high. So,it needs to search some appropriate inhibitors in the separation process, to strengthening inhibition of zinc-sulfide minerals.At the same time,it is necessary to appropriately optimize the parameters of grinding process,to reduce the degree of argillation of the carbonaceous and siliceous gangue minerals.In order to improve the grade and quality of lead and zinc concentrate,it is necessary to find suitable collectors and reduce the viscosity of flotation foam.Through put forward a specific improvement program in order to optimize the existing process and technical conditions,and to provide a high efficiency foundation for carbolic lead-zinc resources recovery.